Model Engine Maker

Help! => Machines, Tools and Fixtures => Topic started by: RayW on March 11, 2018, 03:11:38 PM

Title: Broken vice
Post by: RayW on March 11, 2018, 03:11:38 PM
The jaws on my 6" swivel bench vice have not been locking properly for a while now when they are tightened, suddenly releasing when final pressure is put on the handle. I took it apart today and discovered that the threaded block which moves along the (acme?) threaded shaft has disintegrated. Not only that but the internal thread is completely worn out.
I am sure that someone cleverer than me could quite easily make a new block, but thread cutting is not my forte so looks like a nice new vice will be finding its way to the workshop.
Title: Re: Broken vice
Post by: ShopShoe on March 12, 2018, 12:31:53 PM
A new vice is probably best.

If you are interested in possibly repairing what you have, even if you get a new vice anyway, ACME nuts are sold, as well as ACME threaded rods. In a quick check, both McMaster-Carr and MSC have them.

Title: Re: Broken vice
Post by: RayW on March 13, 2018, 04:04:03 PM
Thanks for that. I picked up a new vice today and promptly took it back! Although it had a nice European type name - Magnussen- it turned out to be cheap Chinese rubbish. The jaws were awful - out of parallel and one sticking up about 1/8" above the other at one end. Also, the diamond pattern on the face of the jaws was so coarse that it was more like sharks teeth, with razor sharp jagged edges at the top.
Fortunately, there was no quibble about a refund, so I am looking round again now.
I have already e-mailed one company in USA to ask about price of posting me an ACME nut but no reply so far. Unfortunately, no-one in UK seems to sell them.
I am reluctant to throw away the old vice if it can be saved as it is a good vice. If I can get an ACME nut, I could make up a new steel block to house it.
Title: Re: Broken vice
Post by: b.lindsey on March 13, 2018, 05:07:44 PM
That sounds like a good plan to me. I doubt that you can get a vise of similar quality for reasonable money. Even the brand names like Wilton and such are mostly made offshore now (China).

Title: Re: Broken vice
Post by: Thor on March 13, 2018, 05:51:43 PM
Hi Ray,
 Could you make the nut yourself? An ACME tap from Tracy Tools is around 30.

Title: Re: Broken vice
Post by: Stuart on March 13, 2018, 06:01:05 PM

These have acme nuts.

Title: Re: Broken vice
Post by: RayW on March 19, 2018, 12:09:23 PM
Thanks all for your suggestions. I did consider buying an ACME tap, but on reading up on ACME thread cutting, it appears that you really need to cut most of the thread on the lathe before using the tap to take out the final bit.
Thanks Stuart for suggesting Roton. I had, in fact, already e-mailed them and after a chase-up e-mail eventually got a reply from them. They said that I really needed to have an account with a courier and that shipping on even a small package like that would be likely to be in the region of $100 !! Clearly, they did not really want to be bothered. When I asked why it couldn't be sent by overseas mail, they told me it would probably get lost anyway!

The outcome is that I now have a fine new workshop assistant, Stanley, aka FatMax! He looks much better made and very smart with the new soft jaws that I treated him to.

I will still see if I can get hold of an ACME nut of some sort as I am sure Stanley would like a companion!
Title: Re: Broken vice
Post by: b.lindsey on March 19, 2018, 12:21:42 PM
That looks nice Ray, the integral anvil may be helpful as well.

Title: Re: Broken vice
Post by: mklotz on March 19, 2018, 02:21:16 PM
In the photo it looks as if the vise is mounted on the bench with its fixed jaw over the bench rather than projecting out a bit from the edge of the bench.  If that's true then you won't be able to hold long items vertically so they project down beyond the front of the bench.
Title: Re: Broken vice
Post by: RayW on March 19, 2018, 04:00:31 PM
Good point Marv. Not sure how much further forward I could bring it due to the size of the base and poisition of the fixing holes. The holes are not equi-spaced so that may help. Failing that, I will just have to use some form of block against the fixed jaw if necessary.

Title: Re: Broken vice
Post by: RayW on March 19, 2018, 04:47:59 PM
How's this for fast action Marv? Just been up the workshop in sub zero temperature and re-located the vice. Fixed jaw now well clear of the edge of the bench.
Thanks for pointing out my blunder!


Title: Re: Broken vice
Post by: mklotz on March 19, 2018, 05:01:56 PM
I wouldn't call it a "blunder"; rather a "slight oversight".  Much more PC, that.

I was going to suggest rotating the base but held back, fearing it might not work.  I'm glad it did.  It's a capability that isn't oft needed but, still, it's nice to have it when you do.

For the benefit of future readers of this thread, I'll mention another concern to keep in mind when mounting vises.  If you intend to use the rotating base to swing long items to a point where they don't interfere with other items in the shop, mount it near the corner of a bench.  This will usually provide a greater angular space in which to orient long work.

Now, to be fair here...I have a swivel base vise too.  In two score years, I've probably rotated it twice; it always seems there's an easier way to get the job done. 
Title: Re: Broken vice
Post by: JC54 on May 28, 2018, 07:35:12 PM
Re your broken vice nut could you mould a new one out of Delrin and mount into a custom build housing? I have done this on my 1910 Drummond lathe. (yes 1910 pre World War !"). There are several articles on the Web about leadnut replacement.  :DrinkPint: